Machine for sealing-in of vitreous bulbs



March 19, 1946. D. MORAND 2,396,301

MACHINE FOR SEALING-IN OF VITREOUS BULBS Filed May 15, 1943 INVENTOR MGEfi/VD.

' WWW ATTORNEY Patented Mar. 19, 1946 MACHINE FOR. SEALING-IN OF VITREOUS BULBS Louis D. Moi-and, Clifton, N. J., assignor to Westinghouse Electric CorporatiomEast Pittsburgh,

a corporation of Pennsylvania Application May 13, 1943, Serial No. 486,834

(Cl. 49-2) l 6 Claims.

This invention relates to the sealing-in of vitreous or glass bulbs and, more particularly, to such used in the manufacture of incandescent electric lamps and similar devices.

The principal object of my invention, generally considered, is toeifect an improvement in the sealing-in of vitreous bulbs and more particularly those used in the manufacture of incandescent electric lamps.

Another object of my invention is to seal the mounts, or flare tubes of electric lamps, into the necks of associated bulbs, while the neck portion below the line of seal surrounds a longitudinally fluted member, whereby during the sealing-in operation holes form at the heat zone provided at the flutes, and flnally the material between said holes is severed and the cullet drops from the bulb.

A further object of my invention is to effect a sealing-in operation between glass bulbs and associated mounts by forcing the bulb neck portions into grooves beyond the line of seal, to cause a series of preferably evenly-spaced holes at said grooves to facilitate severing the cullet from the bulb.

Other objects and advantages of the invention, relating to the' particular arrangement and construction of the various parts, will become apparent as the description proceeds.

Referring to the drawing:

Fig. 1 is a side elevational view of an incandescent electric lamp manufactured ln accordance with my invention.

Fig. 2 is a vertical sectional view, on a larger scale and with parts in side elevation, of a portion of a machine supporting a bulb blank and Nonuniform thickness of the vitreous material or glass in the neck portion of bulbs. such as those used in the manufacture of the customary forms of incandescent electric lamps, results in formation of lumps, large glass beads, and sometimes strings of glass during the sealing-in operation. This retards the cutting-off of the cullet and in many cases forces an operator to pull down to separate it by hand from the sealed lamp. Using my invention will reduce shrinkage caused by leakers due to cracked and imperfect seals resulting from such uneven glass melting.

In order'to overcome the above undesired conditions, -I have provided for the use of an inside collar or generally frusto-conical member, formed with longitudinal, peripheral, preferably upwardly flaring, flutes or grooves, and posi-. tioned inside of the bulb neck below the supported mount or flare tube thereof. The heat zone, which generally involves inwardly directed gas flames, presses the glass inward into the grooves, puncturing the neck between ribs defining the same, thereby causing a series of holes which, if the grooves are evenly spaced as is desirably the case, are also evenly spaced around the neck periphery. Having this series of holes, it is a very easy matter to cut off the small sections of glass therebetween and leave a very uniform seal and lower edge, without any of the disadvantages formerly prevalent. The number associated mount at the beginning of a sealingin operation involving my invention.

Fig. 3 is a transverse sectional view on the line IIIIII of Fig. 2, in the direction of the arrows.

Fig. 4 is a fragmentary vertical sectional view corresponding to Fig. 2, but showing the position of the parts during a subsequent'phase of the sealing-in cycle.

Fig. 5 is a view corresponding to Fig. 4, but showing a later phase of the sealing-in cycle or after the cullet has been severed from the sealed-in bulb.

Fig. 6 is a fragmentary sectional view corresponding to Fig. 5, but on an enlarged scale andshowing a lower portion of a seal-in bulb.

Fig. 7 is a perspective view of. the mount-supporting and hole inciting device.

Fig. 8 is an elevatlonal view of. a cullet after severance from a bulb.

of grooves or flutes for forming holes in thebulb neck depends on the size of the bulb neck, the larger the neck the greater number of flutes, and

- vice versa.

Referring now to the drawing in detail, there is shown in Figs. 2 and 3 a bulb ii of vitreous material or glass desirably supported on a conveyor (not shown) which may be generally of the type indicated by the reference character iii of the McGowan Patent No. 2,212,842, of August a 27, 1940, which conveyor includes a bulb support l2 forming part of a head.

The conveyor is mounted for rotation on a stationary support or standard extending upwardly from its base and within the standard is a hollow post which extends thereabove to support the separate elements, as in said patent. The conveyor carries the heads through a circular path and during a portion of the move-v ment said heads are rotated relative to the .conveyor.

The heads are of similar construction, so a description of one will answer for all. As shown in Fig. 2 each has a rotatable manifold (not shown) carrying burners l3 and II in order to provide a heat zone consisting of gas fires i3 and I3 around the neck of a supported bulb ii. The burners may be rotated by chain means as disclosed in the patent.

The work parts to be fused and united include, the supported bulb i I, which may be placed in position and removed by means of a suitably operated suction cap l1, and a mount 18 consisting of a vitreous or glass flare or stem tube 13, an exhaust tube 2| consolidated therewith, and communicating with the inside of the associated bulb through aperture 22, and a ress 23 through which lead-in conductors 24 and 23 extend to connect with a filament 26 mounted on supports 21 extending from a button 28 of an arbor 29.

During the sealing-in operation the mount is desirably supported by a hollow mandrel or pipe 3i, carrying an inner hollow member 32, on which the flare tube 13 directly rests, and a collar 33 desirably disposed so as to be out of contact with said tube l9 and held in place on the pipe 3| as by means of set screw 34. Said collar is desirably formed of metal, such as steel, which is not adversely afiected by the scaling-in heat. While the lower set-screw carrying portion may be generally cylindrical, as indicated. the upper portion 35 is desirably frusto-conical to a slight extent. The portion 35 is desirably provided with equallyspaced flutes 36 which flare upwardly, or increase in width and depth from a minimum at the lower edge of the irusto-conical portion to a maximum at the upper surface of the member 33, as illustrated, leaving ribs 31 therebetween.

In the present embodiment and for a lamp of the size illustrated, the number of flutes is desirably eight. For a lamp having a larger neck the number may be increased, and vice versa, so that said flutes are spaced circumferentially from 3 4 to of an inch; although I do not wish to be limited to this showing.

The sealing-in operation or union of the parts is desirably effected in accordance with general practice, except as will now be specifically described. A mount it is fed to the supporting portion 32 at one position of a head and a bulb is fed thereover to said head at a subsequent position, so that they become assembled as shown in Fig. 2. Fires I and I6 are rotated about the bulb, while positioned as shown, to eiiect a gradual softening and contraction of the neck about the lower portion of the flare iii to the sealing position where said neck starts to fuse to said lower flange, as shown in Fig. 4.

If desired, air may be introduced into the bulb through the hollow spindle 31, as described in connection with Patent No. 2,212,842 heretofore mentioned, but this is not necessary in accordance with my invention. As the bulb neck contracts and seals to the flare IS, the pressure of the tires and surface tension of the softened glass, causes the latter to be forced in, or contract around the fluted member 35 into the flutes 33, with a formation of holes 38 which gradually expand with an eventual severing of the small sections of the glass 33 therebetween, as shown in F18. 5, resulting in a separation of the cullet II from the bulb as there shown.

While the glass is still hot, air, represented by the arrow 44 in Fig. 5. is desirably blown through the member 3| into the sealed bulb, by means more fully disclosed in said McGowan patent previously referred to, while the same is held down in any suitable manner as by means of the member H, to round-outer finish the seal 42, shown enlarged in Fig. 6, as is customary in such an operation. The bulb and cullet may then be removed from the machine as described in said patant and illustrated in Fig. 9 thereof.

From the foregoing. it will be seen that I have devised an improved apparatus for sealing-in necked bulbs, and particularly such for the manufacture of incandescent electric lamps. The lamps produced in accordance'with my invention involve an improvement as compared with lamps previously manufactured, in that the seal is more regular or uniform, as shown enlarged and in detail in F18. 6, and involves an outstanding regular bead 43 around the lower edge thereof. The cullets removed from such bulbs are found to be uniformly castellated, as illustrated in detail in Fig. 8.

Although a preferred embodiment of my invention has been described, it will be understood that modifications may be made within the spirit and scope of the app nded claims.

I claim:

1. A machine for sealing vitreous bulbs comprising means for holding a bulb with its neck portion lowermost and surrounding the lower end of a flare tube, means for supporting said flare tube, a longitudinally fluted collar, slightly small- ,er in diameter than and over which said neck portion telescopes, mounted on said supporting means adjacent but below and out of contact with said flare tube, and means for creating a heat zone, around the bulb neck between the flare tube and said collar, to seal said neck portion and flare tube, form holes in said neck portion at the flutes, and then sever the vitreous sections therebetween.

2. A machine for sealing vitreous bulbs comprising means for holding each bulb in neckdown position, means for supporting a closing member within the bulb neck, a generally frustoconical member formed with longitudinally extending ribs defining a series of flutes spaced around the periphery of said member and mounted on said supporting means beneath and out of contact with said neck-closing member, and means for creating a heat zone around said bulb neck between said closing member and the upper ends of said flutes, in order to cause the vitreous material to melt, form holes at the flutes, and finally separate at the ribs therebetween, in order to eflect a more uniform seal and severance of the cullet therebeneath.

3. A machine for sealing vitreous bulbs comprising means for holding each bulb inneckdown position, tubular means for supporting a closing member within the bulb neck, a generally frusto-conical member formed with a series of Y upwardly expanding, longitudinally extending flutes defined by peripheral ribs and mounted on said supporting means beneath and out of contact with said neck-closing member, and means for creating a heat zone around said bulb neck between said closing member and the upper ends of said flutes, to cause the vitreous material to seal to the neck-closing member, melt and form holes at the flutes, and finally separate at the ribs'therebetween, in order to eflect a more uniform seal and severance of the cullet therebeneath, said tubular means then serving to blow air into the bulb to round-out the seal.

4. A machine for sealing bulbs to stem tubes comprising a holder for a tube, means for supporting a bulb with a neck portion down 'and surrounding the lower end of said tube, a generally frusto-conical member carried by said holder, closely disposed beneath but out of contact with said item tube, and formed with upwardly expanding grooves, and means for creating a heat zone between the lower end of said tube and the upper end of said grooved member in order to more efficiently efiect a sealing-in and cullet removing operation.

5. A machine for sealing bulbs to mounts of incandescent electric lamps having flare tubes comprising a tubular holder for a mount, means for supporting a bulb with its neck portion down and surrounding the lower end of said mount, a generally frusto-conical member carried by said holder, closely disposed beneath said mount, and formed with a series of upwardly expanding grooves spaced around its perimeter, means for creating a heat zone between the lower end of said mount and the upper end of said grooved member in order to more efliciently efiect a sealing-in and cullet removing operation, and tubular means connected to said holder for forcing air into said bulb to round-out the seal.

incandescent lamps having flare tubes comprising a hollow support, means fitting said support and extending thereabove for holding a mount, means for supporting a bulb with its neck portion down and surrounding the lower end of said mount, a generally frustoconical member mounted on the outside of said hollow support, disposed a short distance beneath the top of said mount holder, and formed with a series of upwardly expanding grooves spaced around its perimeter, and means for creating a heat zone adjacent said grooves and between the lower end of said mount and the upper end of said grooved member in order to more eflficiently seal said bulb neck to said mount, said hollow support serving to convey air under pressure to said bulb to round out the seal.

LOUIS D. MORAND.

6. A machine for sealing bulbs to mounts of 

